Has a radiologist ever challenged one of your orders for an imaging procedure?

An upcoming issue of Renal & Urology News includes a "Legal Issues in Medicine" column about a urologist and a radiologist who were sued for malpractice.
A patient had presented in a hospital emergency department with flank pain and the urologist ordered an excretory urography study for a suspected urinary stone.

The radiologist objected, telling the urologist that unenhanced computed tomography was the standard of care in such cases. The urologist insisted on his way, and the radiologist capitulated. The patient died after going into anaphylactic shock from the intravenous contrast solution.